History of Demolitions of al-Baqi'

The first demolition: In 1220/1805, Wahhabis sieged Medina. When they took over the city, they demolished or seriously damaged the mausoleums of the four Shiite Imams (a) buried in al-Baqi' as well as Qubbat al-Huzn (lit. the dome of sorrow), known as Bayt al-Ahzan, at the command of Saud b. Abdulaziz. According to a report by 'Abd al-Rahman al-Jabarti, Wahhabi forces entered Medina after one and a half years of sieging the city that led to a starvation in Medina. They destroyed all mausoleums and monuments except that of Prophet Muhammad (s).

Reconstruction: The Ottoman government sent an army to quench Wahhabis under the commandership of the king’s son, Ibrahim Pasha. They sieged Medina and killed many Wahhabis and arrested many others who had taken refuge to a fort near Bab al-Shami. Some monuments and mausoleums were reconstructed in 1234/1819 at the command of Sultan Mahmud al-Thani (reign: 1223/1808 - 1255/1839). Saud b. Abdulaziz was defeated and his attempt to convince Muhammad 'Ali Pasha not to surrender him and his fellows to the Ottoman king was unsuccessful.

The second demolition: After another invasion of Medina by Wahhabis in 1344/1926, all historical monuments of the al-Baqi' Cemetery were demolished in accordance with a fatwa of Shaykh 'Abd Allah Balihad, head of Saudi judges, to the effect that visiting graves was polytheistic and heretic. Shawwal 8, 1344/April 21, 1926, the day when the mausoleums of al-Baqi' were demolished, came to be known as "Yawm al-Hadm" (Day of Demolition).

References

The material for this article has been mainly taken from یوم الهدم in Farsi WikiShia.